Surge brake actuator

ABSTRACT

A surge brake actuator is disclosed. The actuator includes an actuator housing and a coupler housing movably engaged within the actuator housing. Upper and lower coupler slide channels formed from a plastic material are releasably connected to the coupler housing and contact the actuator housing. The plastic coupler slide channels reduce frictional loss and provides superior brake actuation output when the coupler housing retracts into the actuator housing during braking. The surge brake actuator includes a push rod assembly that also provides superior brake actuation output to the actuator and can engage the actuator during a breakaway event. The surge brake actuator includes a releasably engagable reverse lock that prevents brake actuation while the towing vehicle moves in reverse.

FIELD OF THE INVENTION

The present invention relates to a surge brake actuator used inconnecting a towed vehicle to a towing vehicle. Particularly, thepresent invention relates to a surge brake actuator that includes ameans for actuating the braking mechanism of a towed vehicle.

BACKGROUND OF THE INVENTION

For towed vehicles, such as trailers, it is common to provide aself-contained hydraulic braking system that operates independently ofthe braking system on the towing vehicle. A surge brake actuator allowsthe towed vehicle to utilize its own braking system that operates whenthe towing vehicle brakes. The surge brake actuator generally includes acoupler housing component attached to the towing vehicle and a hydrauliccylinder component that actuates the brakes on the towed vehicle. Thesurge brake actuator operates in such a manner that when the towingvehicle brakes, the towed vehicle's forward momentum creates adecelerating force on the towing vehicle and the coupler housingattached to the towing vehicle. The hydraulic cylinder utilizes theresultant decelerating force on the coupler housing component to createa fluid pressure that actuates the brakes of the towed vehicle.

The output pressure of the braking system is a function of the abilityof the brake actuator to convert the deceleration forces provided by thetowing vehicle into hydraulic pressure to actuate the towed vehiclebrakes. This force/pressure ratio is an important component in theability of an actuator to provide braking pressure to the towed vehicle.To date, various designs of known brake actuators inefficiently convertthe decelerating force to fluid pressure. Reasons for such inefficientconversion of the decelerating force to fluid pressure include: abuild-up of road debris in the actuator; corrosion or rust bonding ofactuator components; high frictional loss from actuator components; andcoupler housing interference.

Breakaway mechanisms on brake actuators are generally known. Thesemechanisms generally operate through a cable or chain that is attachedto a towing vehicle by means of an S-hook or similar attachment device.The opposite end of the cable is operably connected to the towedvehicle's braking system. When the towed vehicle becomes detached fromthe towing vehicle during operation, the towed vehicle, no longer beingpulled by the towing vehicle, tends to change position relative to thetowing vehicle. The S-hook, however, remains attached to the towingvehicle. As the towing vehicle pulls the cable, the cable actuates thetowed vehicle brake mechanism, thereby stopping the towed vehicle. Tomaintain pressure on the cable and prevent the cable from releasing, thetowed vehicle braking mechanism, a friction lock is generally used toprevent the cable from retracting and prematurely releasing the towedvehicle brake. Although such mechanisms are generally adequate to stop abreakaway trailer in most circumstances, they do possess severalinherent drawbacks.

Most known systems operate by means of a friction lock to prevent theextended cable from retracting. During connection and disconnnection ofthe towed vehicle to the towing vehicle, the cable is often pulledtoward the towing vehicle. Even a slight tug is often enough to actuatethe breakaway mechanism slightly, or to cause dangerous slack in thecable when the friction lock prevents the cable from returning taughtafter connection to the towing vehicle. Even though the brake mechanismmay be actuated only somewhat, this slight activation can causeexcessive wear on the towed vehicle brake and an excessive burden on thepulling vehicle that decreases fuel mileage and increases maintenancecosts. Over time, this excessive burden could even cause the towedvehicle brake to fail in an emergency situation due to premature liningwear or overheating.

Another feature found on certain brake actuators is a reverse lockoutassembly. Known reverse lock-out assemblies prevent accidental actuationof the towed vehicle brakes when the towing vehicle backs up orreverses. These known reverse lock-out assemblies are not reliablebecause they allow for the possibility of accidentally disengaging whilethe towing vehicle moves in reverse. Additionally, the design of thesereverse lock out assemblies are awkward to use, which can also increasethe unreliability of such known assemblies.

It would be beneficial to have a surge brake actuator that can overcomethese problems associated with the inefficient conversion ofdecelerating force to fluid pressure. Furthermore, it would bebeneficial to provide improvements to one or more of the components ofthe surge brake actuator that would improve the force/pressureconversion.

It would also be beneficial to have a surge brake actuator having abreakaway mechanism that safely and reliably operates when the actuatordecouples from the towing vehicle.

It would also be beneficial to have a surge brake actuator having areverse lock-out assembly that is simple to use and reliably preventsbrake actuation when the assembly is engaged and the towing vehicleoperates in reverse while reliably disengaging when the towing vehiclemoves forward.

SUMMARY OF THE INVENTION

A surge brake actuator is provided that includes a coupler housing andan actuator housing that is interconnected with the coupler housing sothat the coupler housing extends and retracts within the actuatorhousing. At least one coupler housing slide channel is connected to thecoupler housing and is in contact with an inner portion of the actuatorhousing. The coupler housing slide channel moves between a towingposition and braking position with the coupler housing while maintainingcontact with the actuator housing.

Preferably, the coupler housing slide channel is plastic. The plasticcoupler housing slide channel reduces frictional losses when theactuator engages from a towing position to a braking position. Also, theactuator preferably includes an upper and lower coupler housing slidechannel connected to the upper and lower sides of the coupler housing,respectively, and in contact with the inner portion of the actuatorhousing. The upper and lower coupler housing slide channels arepreferably connected to the coupler housing by one or more flanges. Theflanges also permit the coupler housing slide to move with the couplerhousing when the actuator is engaged. The upper and lower couplerhousing slide channels also preferably include rails along itslongitudinal edges that prevent the slide channels from moving laterallyon the coupler housing.

A preferred embodiment of the present surge brake actuator includes apush rod assembly having a first end connected to the coupler housingand a second end connected to a braking system that is connected to theactuator housing. The assembly includes a push rod, a compression springsecured to the push rod, a push rod slide connected to the push rod, anda lanyard having an end connected to the push rod slide. Preferably, thepush rod is offset which provides a reduced straight length of the pushrod and exhibits improved resistance to bending over straight push rods.

The push rod assembly can further include a bracket connected to thecoupler housing. An end of the push rod slide is adjacent to thebracket. The bracket transfers the decelerating force on the couplerhousing onto the compression spring through the push rod and into thebraking system. The push rod assembly can also include a retaining pinattached to the push rod to retain the push rod slide. The retaining pinmaintains the radial orientation of the push rod to the braking system.

In another preferred embodiment, the actuator includes a reverse lock.The lock prevents the actuation of the brakes while the towing vehiclemoves in a reverse direction. The lock preferably includes a lever and aengaging portion at an end of the lock. A user pushes the lever towardthe towed vehicle end of the actuator and upward to engage the lock. Thelock further includes a tension spring that assists the lock indisengaging when the towing vehicle moves in a forward direction.

The present brake actuator may further include a breakaway mechanismsystem including a lanyard, lanyard holder, push rod assembly, rotatingroller, roller pin, and upper and lower slide channels. One or morecomponents of the breakaway mechanism system operate if the actuatordecouples from the towing vehicle in order to actuate the brakes of thetowed vehicle.

Still other advantages and benefits of the invention will becomeapparent to those skilled in the art upon a reading and understanding ofthe following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may take physical form in certain parts and arrangementsof parts, a preferred embodiment and method of which will be describedin detail in this specification and illustrated in the accompanyingdrawings that form a part hereof, and wherein:

FIG. 1 shows a perspective view of a surge brake actuator 10.

FIG. 2 shows a cross-sectional side view of a surge brake actuator 10.

FIG. 3A shows a perspective view of an upper coupler slide channel 18.

FIG. 3B shows a perspective view of a lower coupler slide channel 20.

FIG. 4A shows a perspective view of a coupler housing 12.

FIG. 4B shows a perspective view of a coupler housing 12 including upperand lower coupler slide channels 18 and 20.

FIG. 5 shows a perspective, partial cross-sectional view of the couplerhousing 12 including a push rod assembly 40.

FIG. 6 shows a perspective view of a push rod assembly 40.

FIG. 7 shows a perspective, partial cross-sectional view of a push rodassembly 40.

FIG. 8 shows a perspective, partial cross-sectional view of the actuator10 including a reverse lock 70.

FIG. 9 shows a perspective view of a reverse lock 70.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to the drawings, wherein the drawings are for the purposesof illustrating the preferred embodiment of the invention only and notfor purposes of limiting the same, FIG. 1 shows a surge brake actuator10 including a coupler housing 12 and an actuator housing 14. Theactuator housing 14 is preferably constructed of metal and is rigidlymounted to a towed vehicle frame by bolts (not shown) extending throughopenings 15 on the actuator housing 14. The actuator housing 14 not onlyaffords the brake actuator 10 an aesthetically pleasing appearance, butalso protects the components within the actuator 10 from exposure to theelements. The actuator housing 14 includes an open space (not shown) ofadequate size on the bottom side that allows road debris to move throughthe actuator 10 to avoid impeding actuation. The open space creates lesssensitivity to external crushing or bending that would also impedeactuation.

Referring now to FIG. 2, the coupler housing 12 is interconnected withthe actuator housing 14 such that it extends and retracts within theactuator housing 14 in a telescopic fashion. During normal operationwhere the actuator 10 is connected to the towing vehicle and towedvehicle, the coupler housing 12 is in an extended position relative tothe actuator housing 14 when the towing vehicle is not braking, whereasthe coupler housing 12 is in a retracted position relative to theactuator housing 14 when the towing vehicle is braking. Both the couplerhousing 12 and the actuator housing 14 are generally rectangular inshape. The coupler housing 12 includes a ball-type hitch 13 that can beeither rigidly or releasably secured to the coupler housing 12. When theball-type hitch 13 is releasably secured to the coupler housing 12,connecting means such as bolts or any other releasable connecting meanscan connect the housing 12 to the hitch 13. In the particular embodimentshown in FIG. 2, the hitch 13 is integral with the coupler housing 12 sothat the coupler housing 12 is a single-piece construction. Theball-type hitch 13 is secured to the towing vehicle by means of alocking assembly 17 to prevent the hitch 13 from detaching from thetowing vehicle as the towed vehicle is being pulled. The actuator 10 mayoptionally include a damper shock 11 having one end connected to thecoupler housing 12 and another end connected to the actuator housing 14.The damper shock 11 dampens the inertia of the trailed vehicle and actsto smooth out any oscillating or jerking motion between the couplerhousing 12 and the actuator housing 14.

A braking system 16 is located on the inner portion and at the end ofthe actuator housing 14 adjacent to the towed vehicle. The brakingsystem 16 is preferably a hydraulic master cylinder 19 that is operablyconnected to brakes on the towed vehicle wheels (not shown). The mastercylinder 19 includes a reservoir 22 where a user may add hydraulic brakefluid. The master cylinder 19 is secured to the actuator housing 14 byany known connecting means such as bolts.

In operation, when a towing vehicle engages its brakes, a force iscreated on the towing vehicle by the forward momentum of the towedvehicle. This force retracts the coupler housing 12 into the actuatorhousing 14. The retraction of the coupler housing 12 into the actuatorhousing 14 transfers the decelerating force into the braking system 16.The braking system 16 then converts the decelerating force into fluidpressure by moving hydraulic fluid from the master cylinder 19 to thetowed vehicle brakes. The hydraulic fluid transferred to the towedvehicle brakes actuates those brakes.

Once the towed vehicle has slowed down to the towing vehicle speed orthe towing vehicle has sped up to the towed vehicle speed, the couplerhousing 12 moves away from the actuator housing 14 thereby deactivatingthe braking system 16 and releasing the towed vehicle brakes.

Upper and lower coupler slide channels 18 and 20 are attached to thecoupler housing 12. The upper and lower coupler slide channels 18 and 20are preferably molded from a plastic that can withstand high compressionloads and have a low coefficient of friction. The upper and lowercoupler slide channels 18 and 20 contact and slide on the inner wall ofthe metallic actuator housing 14 so that a metal-plastic sliding surfaceoccurs. The metal-plastic sliding surface greatly reduces the frictionalloss between the two components. As the slide channels 18 and 20 arepreferably made of plastic, the channels will not rust which wouldotherwise inhibit actuator movement and output braking pressure.

FIGS. 3A and 3B show the upper coupler slide channel 18 and lowercoupler slide channel 20, respectively. The upper and lower couplerslide channels 18 and 20 include one or more rails 23 along thelongitudinal edges of the slide channels 18 and 20. The rails 23 preventthe slide channels 18 and 20 from moving laterally on the couplerhousing 12. Also, the rails 23 contact the sides of the actuator housing14 so that each of the upper and lower slide channels 18 and 20 contactat least three sides of the actuator housing 14.

One or more flanges 24 are located on at least one of the slide channels18 and 20. Preferably, the flanges 24 are adjacent and extend parallelto the rails 23. One or more recesses 25 are formed between the flanges24. The flanges 24 provide a means of attaching the slide channels 18and 20 to the coupler housing 12. Preferably, the slide channels 18 and20 are attached to the coupler housing 12 as the flanges 34 (see FIG.4A) of the coupler housing 12 fit into corresponding recesses 25 formedbetween the flanges 24 of the slide channels 18 and 20, and the flanges24 of the slide channels 18 and 20 fit into the corresponding recesses35 of the coupler housing 12. The flanges 24 allow the slide channels 18and 20 to move concurrently with the coupler housing 12 when theactuator 10 is engaged. The flanges 24 are preferably rectangular,although other shapes are contemplated.

In addition to the flanges 24, FIG. 3A shows a protrusion 26 molded onthe upper coupler slide channel 18. The protrusion 26 engages a slot 32on the top side of the coupler housing 12 and acts as an additionalflange. Also, the protrusion 26 includes a plurality of teeth 27 thatengage a plurality of teeth 49 on a push rod slide 48 (see FIG. 5) andact as a ratcheting device during a breakaway event. The upper and lowerslide channels 18 and 20 include one or more pins 28. The pins 28 alignand level the slide channels 18 and 20 with the flanges of the couplerslide 24 and act as a shock absorber aligning device. FIG. 3A furthershows a hole 29 on the upper slide channel 18 for accepting a roller pin79 (see FIG. 2). FIG. 3B further shows the lower slide channel 20 havingan embossment 30 molded onto the lower slide channel 20 for accepting aroller pin 79 (see FIG. 5).

FIG. 4A shows the coupler housing 12. The coupler housing 12 includes anopening 32 for receiving the protrusion 26 of the upper coupler slidechannel 18. The coupler housing 12 further includes one or moreapertures 33 for receiving pins 28. The coupler housing 12 includes oneor more flanges 34 that correspond to the recesses 25 of the slidechannels 18 and 20 and one or more recesses 35 that correspond to theflanges 24 of the slide channels 18 and 20.

FIG. 4B shows the upper and lower slide channels 18 and 20 on thecoupler housing 12. The rails 23 of the upper and lower slide channels18 and 20 contact the sides of the coupler housing 12. When the slidechannels 18 and 20 are engaged to the coupler housing 12, spacings 29are formed between the rails 23 of the slide channels 18 and 20 and thewalls of the actuator housing 14 and coupler housing 12. The spacings 29allow road debris and particles to move through and out of the actuator10 and prevent debris and particles from settling in the actuator 10 anddisrupting brake actuation. The spacings 29 also allow for additionalcomponents having a relatively low profile to be included between theside walls of the coupler housing 12 and actuator housing 14 such as areverse lock 70 (see FIGS. 7 and 8) and a lanyard holder 80 (see FIG.1).

In operation, when towing vehicle engages its brakes, the upper andlower slide channels 18 and 20 move with the coupler housing 12 as thecoupler housing 12 retracts within the actuator housing 14. The upperand lower slide channels 18 and 20 slide and maintain contact with theinner wall of the actuator housing 14. The plastic-metal contact betweenthe slide channels 18 and 20 and actuator housing 14 creates lessfriction than the conventional metal-metal sliding.

FIGS. 5, 6 and 7 show a push rod assembly 40 located in the couplerhousing 12 and actuator housing 14. The push rod assembly 40 links thecoupler housing 12 with the braking system 16. The assembly 40 includesa push rod 42, compression spring 44, lanyard 46, push rod slide 48 andbracket 50. The compression spring 44 encircles a portion of the pushrod 42 and has one end contacting the push rod slide 48. The compressionspring 44 acts as a dampening device to limit the hydraulic pressure ofthe braking system 16 and to pressurize hydraulic fluid and maintainpressure during a breakaway event.

The push rod slide 48 is engaged to a portion of the push rod 42. Thepush rod slide 48 includes a collar 51 protruding outwardly on one endof the push rod slide 48. The push rod slide 48 includes a plurality ofteeth 49 on one side of the push rod slide 48. The push rod slide 48further includes a relatively cylindrical aperture 53 (see FIG. 7)located longitudinally within the push rod slide 48 and parallel to thepush rod 42 inserted through the push rod slide 48. A lanyard end 54 islocated in the aperture 53. The lanyard end 54 is preferably cylindricalor circular shaped and has a diameter larger than the width of thelanyard 46. The aperture 53 allows for simple assembly of the lanyard 46to the push rod slide 48 by feeding the lanyard 46 through the aperture53. An opening of the aperture 53 on the end of the push rod slide 48adjacent to compression spring is large enough to allow the lanyard 46to pass through but is too small to allow the lanyard end 54 to passthrough so that the lanyard end 54 is secured to the push rod slide 48.The position of the lanyard 46 and the lanyard end 54 relative to thepush rod slide 48 creates a preferred compression load on the lanyard 46rather than a less desirable bending load. Also, the position of thelanyard end 54 to the push rod slide 48 is adjacent to the longitudinalcenterline of the compression spring 44 so as to reduce as mucheccentric loading of the push rod assembly 40 as possible.

The bracket 50 is connected to the coupler housing 12. The bracket 50includes an opening that engages the push rod slide 48. The collar 51prevents the push rod slide 48 from further moving through the openingof the bracket 50. The bracket 50 and collar 51 allow the push rodassembly to maintain its position relative to the coupler housing 12during normal operation while allowing the push rod 42 to engage thebrake assembly 16 during brake actuation. The bracket 50 allows thedecelerating force of the towed vehicle to transfer to the push rodassembly 40 by transferring the decelerating force to the compressionspring 44 through the push rod 42 and into the braking system 16.

The push rod assembly 40 further includes a retaining pin 52. Theretaining pin 52 is releasably engaged to the push rod 42 and the pushrod slide 48. As the components of the push rod assembly 40 havepre-determined positions, the push rod assembly 40 can be assembled morequickly with the retaining pin 52 than with a screw-type thread design.The retaining pin 52 is releasably engaged into a slot molded into thepush rod slide 48 that maintains the radial orientation of the push rod42 relative to the braking system 16. This radial orientation iscritical as it keeps the push rod 42 from falling to either side of thecoupler housing 12.

Preferably, the push rod 42 is an offset push rod that provides spacesavings by reducing its straight length. The offset design of the pushrod 42 effectively separates the push rod 42 into two shorter sectionsthat can better resist bending due to compression than a push rod havingstraight length design. Therefore, the offset push rod 42 can betterresist deformations generated by abrupt compressive loads. The push rod42 further includes a stopper 43 connected to the push rod 42 andabutting the end of the compression spring 44 opposite the end abuttingthe collar 51 of the push rod slide 50. The stopper 43 maintains theposition of the compression spring 44 on the push rod assembly 40.

In operation, when the towing vehicle brakes, the bracket 50 connectedto the coupler housing 12 moves with the coupler housing 12 as thecoupler housing 12 retracts within the actuator housing 14. The bracket50 pushes the push rod slide 48 and the push rod 42 connected to theslide 48 by way of the connecting pin 52 rearward toward the brakingsystem 16. The push rod 42 slides into the cylinder 19 of the brakingsystem 16, which forces hydraulic fluid out of the cylinder 19 and intothe towed vehicle brakes. The compression spring 44 prevents the pushrod 42 from sliding too far into the cylinder 19.

FIGS. 8 and 9 show a reverse lock 70 that prevents the actuation of thetowed vehicle brakes while backing up the towing vehicle-towed vehicletrailer combination. The reverse lock 70 is located between an innerwall of the actuator housing 14 and a corresponding outer wall of thecoupler housing 12. The reverse lock 70 is pivotally mounted to anactuator housing bolt 71 by a pivot point 79. The pivot point 79 is agenerally ovular or rectangular opening that allows the reverse lock 70to move in a forward or backward position and in an upward or downwardposition.

The lock 70 includes a lever 72 and an engaging portion 73 (see FIG. 9)at an end of the reverse lock 70 adjacent to a coupler housing stud 74and coupler housing bolt 76. The lever 72 protrudes laterally from thelock 70 outwardly beyond the actuator housing 14. The engaging portion73 is contoured, preferably in a substantially semi-circular or U-shapedcontour, to engage the coupler housing 12 by way of a stud 74. The shapeof the engaging portion 73 that engages the coupler stud is sufficientto keep the lock 70 from unintentionally disengaging yet will allow someforward movement prior to releasing from the coupler stud 74.

The reverse lock 70 further includes a retainer 77 that is located onthe top side of the reverse lock 70. The retainer 77 extends inwardlythrough an opening located on the coupler housing 12. A tension spring75 has one end attached to the retainer 77 and another end attached tothe bottom plate of the actuator housing 14. The tension spring 75applies a force to the lever 72 that causes the lever 72 to disengagefrom the coupler stud 74 during resetting. The lock 70 is designed suchthat in the unlikely event that the tension spring 75 becomes disengagedfrom the lever 72, gravity would allow the lever 72 to disengage fromthe coupler stud 74 and permit safe brake operation.

In operation, a user first pushes the lever 72 toward the end of theactuator 10 connected to the towed vehicle and then upward to engage thecontoured engaging portion 73 of the lock 72 to the coupler stud 74. Theengagement of the engaging portion 73 to the coupler stud 74 preventsthe coupler housing 12 from retracting into the actuator housing 14 andthus prevents actuation of the towed vehicle brakes when the vehicletravels in reverse. When the vehicle begins to move forward, the couplerhousing 12 slightly extends from the actuator housing 14 so that thetension spring 75 attached to the lock 70 pulls the lever downward andreleases the engaging portion 73 from the coupler stud 74 to allow brakeactuation to occur in the forward direction.

Referring back to FIG. 1, a lanyard holder 80 is releasably engaged tothe coupler housing 12 by the coupler housing bolt 76. The lanyardholder 80 has a low profile that allows the holder 80 to retract withthe coupler housing 12 into the actuator housing 14 due to the openingprovided by spacing 29 (see FIG. 4B) during normal braking modes. Thelanyard holder 80 maintains the longitudinal position of the lanyard 46to the outer wall of the coupler housing 12 between the towing vehicleand a rotating roller 78 (see FIG. 2). The lanyard holder 80 alsoprevents the lanyard 46 from being accidentally tangled with anycomponent near the towing vehicle end of the actuator 10. A rotatingroller 78 attached to a roller pin 79 is located through an opening onthe coupler housing 12. A groove is located on the rotating roller 78 toretain the lanyard 46 and prevent the lanyard 46 from falling off duringslack conditions. The end of the lanyard 46 opposite end 54 is attachedto the towing vehicle by an attaching means such as an S-hook, clip, orany other attaching means known in the art.

FIGS. 1-6 show the actuator components that form a breakaway mechanismsystem to brake and stop a towed vehicle if the actuator 10 woulddecouple from the towing vehicle. The breakaway mechanical systemincludes the lanyard 46, lanyard holder 80, push rod assembly 40,rotating roller 78, roller pin 79 and the upper and lower slide channels18 and 20. During a breakaway event where the towing vehicle is nolonger attached to the hitch 13, the lanyard end attached to the towingvehicle is pulled through the lanyard holder 80 toward the towingvehicle. Lanyard end 54 is also pulled and manually engages the push rodassembly 40 to actuate the braking system 16 and create braking pressureon the towed vehicle. Since the direction which a towed vehicle wouldde-couple from a towing vehicle is unpredictable, the attachment of thelanyard 46 to the coupler housing 12 must allow for any angle ofdeparture. The engagement of the lanyard holder 80 to the couplerhousing 12 insures that brake actuation occurs at any departure angle ofthe brake actuator 10 from the towing vehicle. Also, the roller 78allows the lanyard 46 to be pulled during a breakaway event withoutaccidental breakage of the lanyard 46 at the roller 78 as the roller 78substantially reduces the force that would cause breakage.

As the lanyard 46 is pulled from the actuator 10 during breakaway, teeth49 of the push rod slide 48 engage the mating teeth 27 on the protrusion26 of the upper slide channel 18. The engagement of the push rod slideteeth 49 with the protrusion teeth 27 prevent the forward motion of thepush rod assembly 40 so that the assembly 40 maintains fluid pressurefrom the braking system 16 to the towed vehicle. Multiple positions ofthe push rod slide teeth 49 and the protrusion teeth 27 provideincremental levels of fluid pressure and prevent accidental disengagingof the push rod assembly 40 to the brake system 16.

The invention has been described with reference to the preferredembodiment. Obviously, modifications and alterations will occur toothers upon a reading and understanding of this specification. It isintended to include all such modifications and alterations insofar asthey come within the scope of the appended claims or the equivalentsthereof.

1. A surge brake actuator comprising: an actuator housing; a couplerhousing telescopically engaged with said actuator housing such that saidcoupler housing extends and retracts within said actuator housing; and aplastic upper coupler housing slide channel conencted to said couplerhousing, said plastic upper coupler slide channel including aprotrustion extending from a wall of said upper coupler slide channelextending within said coupler housing; and a plastic lower coupler slidechannel connected to said coupler housing by way of a plurality offlanges on said plastic lower coupler slide channel that correspond to aplurality of openings on said coupler housing; wherein a portion of saidupper coupler slide channel and said lower coupler slide channel are incontact with an inner portion of said actuator housing.
 2. The surgebrake actuator of claim 1, wherein said protrusion includes a pluralityof teeth on a side of said protrusion.
 3. The surge brake actuator ofclaim 1, wherein said plastic upper coupler slide channel and plasticlower coupler slide channel each further comprises at least one railalong a longitudinal edge of said slide channel.
 4. A surge brakeactuator comprising: an actuator housing; a coupler housingtelescopically engaged with said actuator housing such that said couplerhousing extends and retracts within said actuator housing; a brakingsystem connected to said actuator housing; an offset push rod having afirst end connected to said coupler housing and a second end connectedto said braking system; a push rod slide connected to said offset pushrod, wherein said push rod slide comprises a plurality of teeth on aside of said push rod slide.
 5. The surge brake actuator of claim 4,further comprising a bracket attached to said coupler housing and acollar at an end of said push rod slide, said bracket abutting saidcollar.
 6. A surge brake actuator comprising: an actuator housing; acoupler housing telescopically engaged within said actuator housing; abraking system connected to said actuator housing; a push rod having afirst end connected to said coupler housing and a second end connectedto said braking system; and a push rod slide encircling a portion ofsaid push rod, said push rod slide comprising a plurality of teeth on aside of said puch rod slide.
 7. The surge brake actuator of claim 6,wherein said push rod is an offset push rod.
 8. The surge brake actuatorof claim 6, wherein said push rod slide defines an aperture for theinclusion of a lanyard end.
 9. The surge brake actuator of claim 6further comprising at least one coupler slide channel connected to saidcoupler housing.
 10. The surge brake actuator of claim 9, wherein saidcoupler slide channel is an upper coupler slide channel having aprotrusion extending outwardly from said slide channel.
 11. The surgebrake actuator of claim 10, wherein said protrusion includes a pluralityof teeth on a side of said protrusion.
 12. The surge brake actuator ofclaim 9, wherein said slide channel is plastic.
 13. A surge brakeactuator comprising; an offset push rod; a push rod slide connected to aportion of said push rod, wherein said push rod slide defines anaperture on a longitudinal axis of said push rod slide; and acompression spring encircling a portion of said push rod and abuttingsaid push rod slide.
 14. The surge brake actuator of claim 13 furthercomprising a lanyard having an end releasably secured in said apertureof said push rod slide.
 15. The surge brake actuator of claim 13,further comprising a collar at an end of said push rod slide and abracket, said bracket abutting said collar.
 16. A surge brake actuatorcomprising: an actuator housing; a coupler housing telescopicallyengaged with said actuator housing such that the coupler housing extendsand retracts within said actuator housing; and a reverse lock positionedbetween said actuator housing and said coupler housing, said reverselock comprising a lever extending from said reverse lock, and said lockfurther comprising an engaging portion on an edge of said lock, saidengaging portion releasably engaged to said coupler housing.
 17. Thesurge brake actuator of claim 16, further comprising a tension springhaving a first end attached to said reverse lock and a second endattached to said actuator housing.
 18. The surge brake actuator of claim17, wherein said reverse lock includes a retainer extending from saidreverse lock, said first end of said tension spring attached to saidretainer.
 19. The surge brake actuator of claim 16, wherein saidengaging portion is contoured.
 20. The surge brake actuator of claim 19,wherein said engaging portion is substantially U-shaped.
 21. The surgebrake actuator of claim 16, wherein said engaging portion disengagesfrom said coupler housing when said coupler housing extends from saidactuator housing.
 22. A surge brake actuator comprising: an actuatorhousing; a coupler housing telescopically engaged with said actuatorhousing such that said coupler housing extends and retracts within saidactuator housing; a braking system connected to said actuator housing;an offset push rod having a first end connected to said coupler housingand a second end connected to said braking system; a push rod slideconnected to said puch rod; and a lanyard having an end connected tosaid push rod slide.
 23. A surge brake actuator comprising; an offsetpush rod; a push rod slide connected to a portion of said push rod,wherein said push rod slide comprises a plurality of teeth on a side ofsaid push rod slide; and a compression spring encircling a portion ofsaid push rod and abutting said push rod slide.